A photonic bandgap medium comprises an artificially engineered periodic dielectric array having at least one photonic bandgap, i.e., a range of frequencies in which ordinary electromagnetic wave propagation is strictly forbidden. The presence of these photonic bandgaps can be used to confine and guide electromagnetic waves for any of a variety of useful purposes. Guidance and confinement are achieved by the judicious introduction of defect regions, i.e., missing or differently-shaped portions of the periodic array, within which the electromagnetic waves are permitted to exist and wherealong the electromagnetic waves can be confined and guided.
Arrangements have been proposed for modulation of photonic bandgap materials to provide variation in the way incident radiation is propagated by the material. However, issues remain for each such proposal with respect to one or more of spatial resolution, spatial design flexibility, power requirements, and spatial power control. Other issues remain as would be apparent to one skilled in the art upon reading the present disclosure.